What does Mark 13:11 mean?

When they arrest you and drag you in, don't stress about what to say ahead of time. Just say whatever comes to you in that moment, because it won't really be you talking—it's the Holy Spirit speaking through you. Mark 13:11 - Modern Text Bible

(Jesus reassures them that when they're put on the spot, God will give them the words they need. They don't have to prepare speeches; the Spirit will help them.)